Hi Malcolm

I seem to be the second user with this problem, so I was interested in what you have tried so far. I seem to have found a work around in Firefox. I am not totally happy with it, that is why I would not claim it as a solution.

Workaround: In Firefox type about:config in the address bar, then locate browser.download.manager.scanWhenDone and set to false. I have not tried the same trick in Thunderbird yet, but I expect similar behavior.

Here is some more detail in case you see anything to help, or someone else can shed any more light on this.

I see the problem in Firefox 7.01, 8.0 beta and Thunderbird 7.01 on Windows 7 Home Premium. I can download PDF in Chrome. I have not compared Chrome's settings to Firefox yet. I am also using AVG and Zone Alarm. I think we can dismiss Zone Alarm, as the file obviously makes it to the download directory before being deleted. In the case of Thunderbird the PDF sits happily as an attachment on an email that is stored locally, but cannot be saved as a stand alone file. My email should have been scanned for viruses before it reached my inbox, by AVG.

As the downloaded files appear for a short time, I tried to open them before they disappeared. I only managed this once by double clicking. The PDF opened in acrobat viewer and this locked the file and prevented the delete. I manually scanned the file with AVG and it found no problem. Because Firefox was set to trigger a scan, this may have bypassed the temporary disable setting in AVG when I tried that unsuccessfully. According to Windows, there is no other antivirus running.

The missing files do not show up in AVG's history. There is no sign of them in quarantine, or in the Windows recycle bin. I am trying to use the file access auditing to identify what program is doing the delete. I have set up the audit properties on one specific sub-directory, but all the instructions on how to turn it on use gpedit which is not available in the home version. If I can identify the equivalent registry settings, then I will post the results of this experiment.

I have the same issue with JPG, using save image and the Firefox Troubleshooting information page! As an interesting aside, I found that the CSS and JS files that accompanied this when I saved the complete web page did remain. If this is because Firefox only asks for the main file to be scanned, then this could point to a different potential bug.

If I enabled the acrobat plug in, then the PDF would appear inside the browser window. Likewise, the JPG that I tried to download, was also displayed OK. This does not help other file types.

I have not done a full file type audit, but I can add exe to your list. I tried to download the production version 7 rater than the version 8 beta. In the end I had to use Chrome to get another version of Firefox (how embarrassing). I also suspect that the automatic update is broken by this issue.

If anyone can provide any extra help, or guidance, I will be grateful too.

I found this: [https://bugzilla.mozilla.org/show_bug.../show_bug.cgi?id=427258] and [https://bugzilla.mozilla.org/show_bug.../show_bug.cgi?id=488672] which appears to match this problem exactly, except that it was first reported on FF3 on Vista. Also [http://kb.mozillazine.org/Unable_to_s.../Unable_to_save_or_download_files] gives generic advice.

I need to look into the bug reports to see if there are any viable workarounds. It did just remind me that I upgraded AVG from 2011 to 2012 about the time that I first saw the issue, so some registry corruption is not out of the question.

I fixed my problem. From the bug reports, it appears that this problem is caused by a misconfiguration of Windows anti-virus. FF & TB call the AV for any file that is downloaded by default. In my case it seems that the AVG2011 to AVG2012 upgrade went wrong and did not clean up properly. I found residual traces of AVG2011. Fortunately I was lucky enough to avoid a trawl through the registry: Control Panel > Programs and Features > right click AVG2012 and select Change. I then selected the Repair option.

I hope this helps, but it might not be as simple to fix in all cases. I would recommend reading through the bug report threads and following any related bug links as there is more useful information there.

Hi David_O,

Thanks for your feedback, much appreciated. This issue is finally solved for me also. Not only in FF & TB but also in IE9 where a message window appeared telling me a virus was found and the downloaded attachment was deleted.

I did change the config settings in FF and TB to not scan downloads and was then able to save and open files and email attachments. However, I also use Outlook Web Access in the IE Tab 2 add-on in FF and still could not save attachments from web mails on either of my computers.

I opened Outlook Web directly in IE9, where I had the same deleted email attachment issue but with a virus found message.

AVG was the culprit.

On my laptop, I had uninstalled AVG with the uninstall tool listed below and installed Avast! Free antivirus, but still had the same deleted email attachment issue.

On my desktop computer, I had AVG2011 and AVG2012 installed (...AVG2012 did not uninstall AVG2011...) and also had the same deleted email attachment issue.

Today, I tried to uninstall AVG2011 with the uninstall tool in the Menu folder, but that would not work. In desperation, I downloaded the AVG uninstall tool found at http://www.avg.com/us-en/faq.pnuid-1843780517 onto my desktop computer and ran it over and over again, rebooting the computer each time, testing the download issue in IE9 using Outlook Web Access, until finally, I could save and open an email attachment. This happened when finally, both versions of AVG were completely uninstalled.

After my success, I ran the AVG uninstall tool using the same process on my laptop, even though I have Avast! installed - and - all problems solved.

I reinstalled AVG2012 on the Desktop, reset FF and TB to scan emails and have no more issues (for now).

I suppose the moral of the story is: when uninstalling AVG Try, Try, and Try Again.